The invention relates to internal combustion engines for marine propulsion devices, and, more particularly, to means for securing the flywheel to the crankshaft of such internal combustion engines.
In the marine art, it is common to use tensile means (means placing a tensile load on the crankshaft) engaging the flywheel and the end of the crankshaft for securing the flywheel to the crankshaft. In the usual arrangement, the crankshaft has an externally threaded end, and a tapered portion located inwardly of the threaded end. The flywheel has a frustoconical aperture which receives the tapered portion of the crankshaft, and a nut threaded onto the end of the crankshaft secures the flywheel to the crankshaft by forcing the flywheel onto the tapered portion of the crankshaft.
This arrangement places a tensile load on the tapered portion of the crankshaft because the nut exerts an axially outward force on the end of the crankshaft, and the flywheel exerts an axially inward force spaced from the end of the crankshaft on the tapered portion of the crankshaft. This tends to "stretch" the tapered portion of the crankshaft in the axial direction, thereby lessening the junction between the flywheel and the crankshaft.
Typically, the flywheel is aligned with the crankshaft for timing purposes by slot and key means between the flywheel and the tapered portion of the crankshaft.
Attention is directed to the following U.S. patents:
Arden--U.S. Pat. No. 2,353,431--July 11, 1944 PA0 Lagervall--U.S. Pat. No. 2,815,972--Dec. 10, 1957 PA0 Janiszewski--U.S. Pat. No. 3,279,870--Oct. 18, 1966 PA0 Ayson--U.S. Pat. No. 3,413,926--Dec. 3, 1968 PA0 Gladieux--U.S. Pat. No. 3,899,257--Aug. 12, 1975 PA0 Pichl,--U.S. Pat. No. 4,241,620--Dec. 30, 1980 PA0 Honda--U.S. Pat. No. 4,262,552--Apr. 21, 1981 PA0 Anderson--U.S. Pat. No. 4,276,783--July 7, 1981 PA0 Heitmann--U.S. Pat. No. 4,340,317--July 20, 1982 PA0 Sheppard--U.S. Pat. No. 4,411,549--Oct. 25, 1983 PA0 Ban--U.S. Pat. No. 4,520,688--June 4, 1985